Welcome to my J.A.M. (Just Ask Mike) Session, a weekly column where I answer your basic electrical questions. If you’re a newbie who’s never plugged in a shore power cord (or ask – what’s a shore power cord?), or wonder why your daughter’s hair dryer keeps tripping the circuit breaker, this column is for you. Send your questions to Mike Sokol at mike (at) noshockzone.org with the subject line – JAM. Today Mike discusses how much amperage kitchen appliances use.
Dear Readers,
Apparently I don’t have enough to do, so I prowl around on other forums and groups watching for electrical trouble. And sometimes the bat-signal goes up from another forum member who knows me.
Here’s what I saw the other day on the Thor ACE Motorhome Facebook Group that I think is worthy commenting on here. Yes, it’s about those high-amperage electrical kitchen appliances and why they can be trouble in a 30-amp RV.
Yes, I know that air frying is a healthy alternative to deep frying in oil. Yes, I know it tastes great. And, yes, this could help feed the kids and grandkids with all kinds of healthy and tasty snacks while camping.
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So what’s the problem?
Note that the poster is having problems tripping the 30-amp circuit breaker in their shore power. Let’s see if we can come up with a possible solution.
Here’s the amount of power available for 20-, 30- and 50-amp shore power connections. You can see that the humble 20-amp “Edison” outlet in your house has a maximum available current of 20 amperes, which works out to 2,400 watts of power. That’s because amps x volts = watts. If we know the voltage (120 volts) and the wattage of an appliance, to find the amperage we simply calculate watts / volts = amps. So a 1,200-watt appliance divided by 120 volts equals 10 amps, as in 1,200 watts / 120 volts = 10 amps. Easy, eh?
What about running my waffle iron or hair dryer or Ninja Air Fryer?
Well, many of those appliances have a wattage rating listed online, but sometimes finding the amperage draw is a bit tricky, but here’s how to do it. As near as I can tell, this Ninja Air Fryer draws 1,750 watts which is 14.5 amperes of current. As above, just divide the appliance’s listed wattage by 120 volts to find out just how much amperage it draws.
- 1,800 watts / 120 volts = 15 amps
- 1,500 watts / 120 = 12.5 amps
- 1,200 watts / 120 = 10 amps
- 1,000 watts / 120 = 8.33 amps
- 800 watts / 120 = 6.66 amps
- 600 watts / 120 = 5 amps
Now all you have to do is add them up to make sure you don’t go over your allotted 30 amps of pedestal current. Let me throw in three more numbers you need to be aware of.
- Electric water heater element = 1,500 watts (12.5 amps)
- Lithium battery 60-amp charger = 1,000 watts (8.33 amps)
- Lithium battery 80-amp charger = 1,300 watts (10.83 amps)
- Rooftop A/C unit (13,500 BTU) = 1,600 watts (13.3 amps)
- Rooftop A/C compressor has a 50-amp (or more) starting surge
Once everything you turn on gets close to 30 amps on a 30-amp shore power outlet, or 50 amps per leg on a 50-amp shore power outlet, you’re probably going to trip the circuit breaker before too long.
I think that Green Acres had the right idea back in their 1965’s SitCom where they marked all the extension cords with numbers and knew what combinations would work, and what would probably blow a fuse. I think a chart showing you what combinations you should avoid is a great idea.
So is there a workaround?
Well, sort of kind of. While you can’t get more energy from the 30-amp pedestal outlet, if the campground has a 20/30/50-amp pedestal, it’s likely that the 20- and 30-amp outlets are on separate poles. So the 30-amp outlet would be on hot-leg 1, and the 20-amp outlet would be on hot-leg 2.
If that’s the case, then you could simply run a separate heavy-duty, 12- gauge extension cord from the 20-amp pedestal outlet and plug it directly into your Ninja fryer. This is actually allowed by code, while connecting a second shore power cord directly into your RV is a code violation.
Now, if this trips the 30-amp breaker feeding the pedestal, then there’s not enough amperage at the pedestal to use the 30-amp and 20-amp outlets at the same time. In any event, don’t be tempted to try one of the so-called 45-amp adapters to plug a 50-amp shore power cord into both 30- and 20-amp outlets. Because there has to be a GFCI outlet on any outside 20-amp outlet, it will instantly trip. So don’t waste your money and time on it.
OK, everyone. Remember that electricity is a useful and powerful force, so we all need to pay attention to safety precautions while using it.
Let’s play safe out there….
Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.
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I have an inverter question. I have a new van and want to use only an inverter to power only things like my tooth brush or my phone, etc… Except I love my ninja foodi air fryer. I have an 800 watt and an 1800 watt inverter but the second takes up alot more space than the first. Will the ninja run on the lower watt power source but just not get as hot? Does it have any diodes that would not allow it to work at all? Will I ruin it if I try?
An 800 watt inverter doesn’t have a chance at running a Ninja Air Fryer. I don’t think it will harm the Ninja, but the 800-watt inverter will quickly shut down, hopefully without damaging itself. The 1800 watt inverter should work, but only if it’s a pure sine wave type. If it’s a Modified Sine Wave MSW inverter it could possibly burn up the control circuitry in your Ninja air fryer.
Be aware that an 1800 watt load on an inverter will draw about 150 amps from your battery. And it will drain a 100 amp AGM or Flooded Lead Acid battery down to 50% State of Charge in around 20 minutes of fry time.
Heck, I’ve just learned to use the Foodi by itself. We can use the microwave and gas burner at the same time. Can’t use the teakettle to boil water at the same time though. No big deal.
The Foodi is wonderful.
Mike, you stated: “If that’s the case, then you could simply run a separate heavy-duty, 12- gauge extension cord from the 20-amp pedestal outlet and plug it directly into your Ninja fryer. This is actually allowed by code, while connecting a second shore power cord directly into your RV is a code violation.”
If I add a seperate 20A outlet inside the RV connected to a 20A marine grade inlet on the outside of the RV, can this be used in compliance to code? There is no mixing of power. Just a totally seperate outlet for a small appliance that is fed by a 20A cord.
Thanks.
Technically that is still a code violation but it’s not about the mixing of power. According to my code authorities it’s so that firefighters only need to turn off one source of electricity when responding to a fire, which seems illogical since the 20 and 30 amp breakers are next to each other in the pedestal. I suspect it’s more about limiting total amperage draw from each pedestal that can contribute to voltage brownouts in campgrounds. But realistically I see this sort of thing being installed in RVs all the time. However a campground could ask you to disconnect your second power cord from your RV and say it’s a code violation. But you could put your Ninja air fryer on the picnic table, plug it into the same 20-amp outlet with the same extension cord, and be code compliant. Seems crazy, but that’s how the code reads.
This Pro Grip® 1-1/2′ 10/3 STW 50M-30F Right Angle RV Adapter may cause a problem. Because in this case your lead in wire to your RV is designed for a 30 amp service max and this adapter is plugged into 50 amps socket. After it reaches the main breaker panel in the RV all is good because everything after that is protected by a 30 amp breaker. But if you have a short on the 30 amp rated lead in wire it pedestal breaker wont trip until you hit 50 amps which makes that lead in a fire hazard.
Can you just upgrade to 50 Amp from a 30 Amp coach? 2020 Newmar BSS 3014
Yes, you can contact http://www.rvcomfortsystems.com and they will send you a wire diagram with a list all the Home Depot parts you need to to this.
Thanks Larry. It looks like the link you sent was only about heating systems. I want to upgrade whole coach to 50 AMP service. Did I miss something?
I solved this problem with a 20 amp 3-way switch which sends power to the oven or the water heater but not both at the same time.
A slight correction on the charger ratings.
An 80 amp lithium charger is rated for 1300 watts (10.83 amps) and a 60 Amp LI charger is rated for 1000 watts (8.33 amps).
Thanks for keeping me 100% accurate. I’ll correct the copy…😁